Add type .ico (#1)

src/lib.rs

@@ -37,6 +37,8 @@ pub enum Type {
     Rgb,
     /// FLIF (Free Lossless Image Format) files
     Flif,
+    /// ICO files
+    Ico
 }
 
 

src/patterns.rs

@@ -16,6 +16,7 @@ const BMP: &'static [u8] = b"BM";
 const BGP: &'static [u8] = b"BPG\xfb";
 const RGB: &'static [u8] = b"\x01\xda";
 const FLIF: &'static [u8] = b"FLIF";
+const ICO: &'static [u8] = b"\x00\x00\x01\x00";
 
 #[inline]
 fn is_pbm(ref bytes: [u8; 32]) -> bool {
@@ -51,6 +52,7 @@ pub fn guess(ref bytes: [u8; 32]) -> Option<Type> {
         _ if &bytes[..4] == BGP => Some(Type::Bgp),
         _ if &bytes[..2] == RGB => Some(Type::Rgb),
         _ if &bytes[..4] == FLIF => Some(Type::Flif),
+        _ if &bytes[..4] == ICO => Some(Type::Ico),
         _ if is_pbm(*bytes) => Some(Type::Pbm),
         _ if is_pgm(*bytes) => Some(Type::Pgm),
         _ if is_ppm(*bytes) => Some(Type::Ppm),

tests/mod.rs

@@ -99,6 +99,11 @@ fn test_flif() {
     assert_result!(Some(imghdr::Type::Flif), "./tests/images/example.flif");
 }
 
+#[test]
+fn test_ico() {
+    assert_result!(Some(imghdr::Type::Ico), "./tests/images/example.ico");
+}
+
 #[test]
 fn test_not_a_image() {
     assert_result!(None::<imghdr::Type>, "./tests/images/not-a-image.txt");